Norwegian is to become the first budget airline to operate flights between the UK and Brazil.
The Scandinavian airline will operate four weekly services between London Gatwick and Rio de Janeiro from March 31 next year.
This puts it in direct competition with British Airways, which is the only other airline flying non-stop between London and Rio.
Test bookings by the Press Association for three return flights from London to Rio in April and May on hand baggage-only fares found that passengers could book with Norwegian for between £480 and £540, compared with between £721 and £763 with BA.
BA’s flights are a daily service to and from London Heathrow and its fares include food and drink, while Norwegian customers travelling on the cheapest tickets must pay extra if they want refreshments.
There is also a more generous hand baggage allowance with BA.
Norwegian is also extending its South America operation by increasing its Gatwick-Buenos Aires flights from four per week to a daily service from December 3 “in response to customer demand”.
In October, the airline launched domestic flights in Argentina with two routes from Buenos Aires to Mendoza and Cordoba.
Norwegian chief executive Bjorn Kjos said: “We’re building on our expansive global network by launching the UK’s most affordable flights to Brazil and making South America available to even more consumers.
“Our new Rio de Janeiro route breaks the monopoly on direct flights between the UK and Brazil as we’re committed to lowering fares and making travel more affordable for all holidaymakers and business travellers.
“Brazil is a fantastic addition to our global network and we look forward to welcoming customers on board.”
Norwegian has shaken up the long-haul aviation market in recent years by offering flights at knockdown prices.
Some of its most popular deals have included £99 transatlantic flights to New York.
The airline has struggled to contain costs during its growth, and had around £2 billion of net debt at the end of last year.
Ryanair boss Michael O’Leary predicted it would “go bust this winter”, but the Scandinavian carrier insisted his comment has “no root in reality”.
Two budget carriers – Primera Air and Cobalt Air – collapsed last month.
Aviation experts believe there will be an increase in airline consolidation in the coming months.
BA’s parent company IAG acquired a 4.6% share in Norwegian in April and has subsequently made two takeover offers, which were rejected.
IAG said it was “considering its options”, while Norwegian insisted it “remains fully committed to delivering on its stated strategy”.